Need some help please

Hunter44

Hunter44

Well-Known Member
Joined
Feb 26, 2014
Location
Lexington
Recently finished up swapping in 5" trail gear springs front and rear. Few concerns I have and I want yall's professional opinions/advice. For one my truck wonders crazy on the road, the draglink is too long I believe but its as parallel to the tie rod as possible so what's the problem? Secondly, my rear axle is pushed back what looks like 2-3", how should I go about fixing it but keep my shackle angle like it is?
 
Hunter44 said:
Recently finished up swapping in 5" trail gear springs front and rear. Few concerns I have and I want yall's professional opinions/advice. For one my truck wonders crazy on the road, the draglink is too long I believe but its as parallel to the tie rod as possible so what's the problem? Secondly, my rear axle is pushed back what looks like 2-3", how should I go about fixing it but keep my shackle angle like it is?
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What sort of truck is it? Toyota?
 
Since you have messed with the geometry of the truck, you'll need to get it lined up. The wondering is usually one or both of two things, tire wear, or one tire fighting the other, If you don't have the drag link set up right, it can cause this. Also lifting it, will add more stress on worn TRE's. You may also develop the dreaded death wobble too.
Jack it up rest the axle on jack stands, grab the tire and see if you have movement in the tires. then get trusty measuring tape and measure middle tire front to back. Should be same. also do top of tire and bottom of tires, if not same there, could be bearing or ball joint issues.
 
toyta.jpg
this truck?
 
It's a 95 toyota pickup. Brand new 42" military tires running 55psi. I'm running heim joints and 1 ton axles. You can see the truck in the Builds section
 
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Get everything lined up properly, including the rear axle, then get it aligned. Improper toe and caster settings can cause wandering, and any problems will also be amplified by the higher center of gravity with the new springs. You've changed the resonant frequency of the chassis/body with respect to the axles, because the center of gravity is a different distance away from the axles, and the spring rate has also changed. So the loads on the suspension from the body/chassis are now different (more motion and/or different frequency) during any direction changes, and during any other event that makes the body/chassis move.

The amount of toe changes the preload on the tire sidewall, increased toe (either toe out or toe in) has a dramatic effect on steering responsiveness because you don't have to take the "slack" out of the sidewall when changing direction. Caster is what changes the amount of steering self-centering effect (among other things), so if you've decreased the amount of caster then you've likely made the steering a lot more vague and a lot more likely to track in some other direction with very little effort.

The drag link length isn't too important, except for steering symmetry. It's not going to cause the problems you're talking about. If it's the wrong length, the Pitman arm starts off on the wrong side of center which makes the steering response different from left to right, but the change in drag link angle from left to right (depending on the amount of lift) also changes that. So don't be concerned about the length for now and worry about the much more important issues of alignment and proper axle location.
 
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To answer your specific question, the only way to change the axle location and keep the shackle angle the same will be a different length spring (or at least a modified mounting location along the spring arc ) or a different spring rate.

Fabrik8 just gave you a TON of info as well. I'd suggest digesting it and asking questions for what you don't understand.


Throwing shit against the wall without more info I'd suspect that you need to cut and turn your perches to eliminate the wobbling.
 
Hunter44 said:
Don't have a panhard bar.
Caster is 9*
No idea what toe is, haven't measured
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There's a big problem right there. With those talk springs you need a panhard bar. It needs to be same length and angle as drag link as to no have bump steer.

9* is acceptable but a bit excessive for a 60 front. 6* is closer to factory. You will have better return to center but should notice some jacking in the side in the same direction when turning.

Toe is a big part of the truck wandering as the vehicle is unsure of which front tire track to follow.

1/8" is factory gm one ton front.

I run 1/4" toe in on my 60 front with 42's with 5 psi air, and it doesn't wander.

Over 3/8-1/2" would be excessive toe in.

Any toe out is unacceptable.

Toe in is required as their is great wind resistance on the front of the tires as you go down the road. Even with all brand new parts there is a small amount of play in all the parts, bearings, hubs, kingpins, etc. Toe in allows for this and as the wind pushes the tires outward at road speed takes all the play out of system, leaving the tires parallel when at speed. This give a "tight" steering feel.
 
Hunter44 said:
Don't have a panhard bar.
Caster is 9*
No idea what toe is, haven't measured
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Track bar and Panhard bar are two different names for the same thing. You've got one unless you have some other way of laterally locating the front axle housing.

If you don't have one, that would explain a lot, and make it a death trap to drive at anything but really slow speeds.
 
If you haven't been following his build, one thing he didn't mention here,; he went from taller springs down to 5". I'm guessing he didn't have the issues before, and why he's asking now.

I would check to make sure all your bushings & steering parts are tight, then check toe as most mentioned. Might also check to see if your agreeing is centered, to see if the drag link is now to long
 
Drop the tire pressure to around 30 and see how that does. At 55 psi, it's probably only riding on the center of the tires and has basically zero traction, get that caster between 3 and 5 degrees positive, and get an alignment. A real one on an alignment rack. It's not impossible unless whoever you take it to is just being a lazy ass.

If the drag link is too long, cut one end off and weld in a new threaded insert.
 
You don't need much to check toe in with a tape measure.

Just two straight edges across the tire horizontally, near the tire center.

These need to be longer than the tire diameter to get measurements front and rear of the front tires.
 
I've used 2 wooden yardsticks rubber banded together to check toe in on straight axles. Expand them carefully to touch the widest part of the sidewall inline w the axle, mark or record the length and repeat on the other side of the axle and adjust as needed. Sometimes a short drive and another adjust are needed for best results.
 
mommucked said:
I've used 2 wooden yardsticks rubber banded together to check toe in on straight axles. Expand them carefully to touch the widest part of the sidewall inline w the axle, mark or record the length and repeat on the other side of the axle and adjust as needed. Sometimes a short drive and another adjust are needed for best results.
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Take a pair of gallon freezer bags, put a little grease in each one, and smoosh it all around then flatten the bag. Put one under each tire, and you now have cheap slip plates to adjust things like toe without tire binding. If you really want to be anal, roll back about 2 feet after an adjustment and then roll forward back onto the bags, which will free up binding ever better.
 
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